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Maximum Insufflation Capacity^*

^* From the Department of Physical Medicine and Rehabilitation, University of Medicine and Dentistry of New Jersey-The New Jersey Medical School, Newark, NJ.

Correspondence to: John R. Bach, MD, FCCP, Professor and Vice Chairman, Department of Physical Medicine and Rehabilitation, University Hospital B-403, 150 Bergen St, Newark, NJ 07103; e-mail: bachjr{at}umdnj.edu

	Abstract

TOP Abstract Introduction Materials and Methods Results Discussion References

 
Objective: To investigate the effect of deep lung insufflations on maximum insufflation capacities (MICs) and peak cough flows (PCFs) for patients with neuromuscular disease.

Method: Forty-three patients with neuromuscular disease were trained in stacking delivered volumes of air to deep lung insufflation and were prescribed a program of air stacking once their vital capacities (VCs) were noted to be < 2,000 mL. VC, MIC, and unassisted and assisted PCF were monitored. The initial data were compared with the highest MICs subsequently achieved. For those patients whose MICs only decreased, we compared the initial data with the most recent data.

Results: The MICs increased from (mean ± SD) 1,402 ± 530 mL to 1,711 ± 599 mL (p < 0.001) for 30 patients and only decreased for 13 patients. Patients for whom the MICs increased also had a significant increase in assisted PCF from 3.7 ± 1.4 to 4.3 ± 1.6 L/s (p < 0.05) despite having somewhat decreasing VCs and unassisted PCFs.

Conclusion: With training, the capacity to stack air to deep insufflations can improve despite progressive neuromuscular disease. This can result in increased cough effectiveness.

Key Words: cough • maximum insufflation capacity • neuromuscular disease • peak cough flow • pulmonary compliance • range-of-motion therapy

	Introduction

TOP Abstract Introduction Materials and Methods Results Discussion References

 
Neuromuscular diseases are characterized by progressive weakening of skeletal, respiratory, bulbar, and, in the case of myopathies, cardiac muscles. Diagnoses are made on the basis of electrodiagnosis, muscle or nerve biopsies, elevations of serum muscle enzymes, and, in the case of Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA), and a few rare conditions, by cellular DNA analysis. The inability to effectively cough out airway secretions is the main cause of respiratory failure and death for these patients.¹

Normal breathing consists of varying tidal volumes with intermittent deep breaths or sighs.² Periodic hyperinflation is required to prevent closure of lung units.³ Patients with neuromusculoskeletal disease can have severe inspiratory and expiratory muscle weakness that diminishes tidal volumes, sighs, and cough flows, resulting in little expansion of the lungs and chest walls.^{4 5} This leads to stiffening of the rib cage and a reduction in chest wall compliance.^{6 7} Reduction in lung compliance and in lung and chest wall range of motion (ROM) also may be related to alterations in the elastic properties of lung tissues caused by the diminished lung volumes.⁸

During a normal cough, about (mean ± SD) 2.3 ± 0.5 L of air is expelled⁹ at flows of 6 to 20 L/s¹⁰ after glottic closure of about 0.2 s. High thoracoabdominal pressures are needed to generate effective cough flows on glottic opening. Thus, an effective cough requires deep lung volumes and breath holding.^{10 11 12} A deep breath dilates the airways, increases the force of expiratory muscle contraction, and increases lung recoil pressure.² Breath holding facilitates the distribution of air to the lung periphery and causes intrathoracic pressure to increase.¹³ Thus, it is not surprising that assisted peak cough flows (PCFs) can be significantly increased from maximal insufflations.¹⁰

The maximum insufflation capacity (MIC) is a function of oropharyngeal and laryngeal muscle function and, to some degree, of pulmonary compliance.¹⁴ We hypothesized that patients with neuromusculoskeletal disease who have diminished vital capacities (VCs) but adequate bulbar muscle function could benefit from training in and prescription of a daily program of air stacking to maximal lung insufflation, increasing MICs and assisted PCFs. The essential purpose of this study was to investigate the effect of lung ROM therapy on MICs and assisted PCFs.

	Materials and Methods

TOP Abstract Introduction Materials and Methods Results Discussion References

 
All patients with neuromusculoskeletal disease diagnosed by standard criteria¹⁵ and monitored in a Jerry Lewis Muscular Dystrophy Association clinic were candidates for this study, provided that they were old enough to cooperate. The exclusion criteria for taking part in the deep insufflation program were the following: VC > 2,000 mL; the presence of concomitant intrinsic lung disease to the extent of necessitating oxygen therapy; bulbar muscle dysfunction so severe that glottic closure could not be attained and the MIC, therefore, could not exceed the VC; the presence of an indwelling tracheostomy tube; the inability to cooperate because of mental retardation; and failure to return to the clinic for reevaluation. Chronic lung disease was defined by a baseline oxyhemoglobin saturation that is chronically < 95% despite eucapnia and the absence of airway mucus accumulation, or an FEV₁/FVC ratio < 2 SDs of normal.

The pulmonary function testing was performed by a respiratory therapist who had no idea that the data would be used for a study. The data analysis was retrospective, and the study was conceived after all of the data had been collected.

The patients were trained in air stacking in the clinic and were prescribed 10 to 15 maximal lung insufflations by air stacking three times each day from the point at which their VCs were noted to be < 2,000 mL. The VC, MIC, and unassisted and assisted PCFs were evaluated, and patients within 100 miles of the clinic were asked to return for reevaluations every 6 months. The MIC by air stacking was achieved by the patient taking a deep breath, holding it, and then air stacking consecutively delivered volumes of air to the maximum volume that could be held with a closed glottis. The air was delivered from a manual resuscitator or portable volume ventilator via a mouthpiece or nasal interface. The patient then exhaled the maximally held volume of air (MIC) into a Wright spirometer (model Mark 14; Ferraris Development and Engineering Co, Ltd; London, UK), and both the VC and the MIC were measured. The maximum values that were observed in four or five attempts were recorded.

Unassisted PCFs were measured by having the patient cough as forcibly as possible through a peak flowmeter (Assess; Health Scan Products Inc; Cedar Grove, NJ). To measure assisted PCFs, the patient was insufflated to a deep insufflation and then asked to cough forcefully through the peak flowmeter as an abdominal thrust was timed to glottic opening. The maximum observed flows in four or five attempts were recorded. Forced expiratory flows other than cough flows were also measured (Microspiro HI-501; Chest Corp; Tokyo, Japan).

The data at the initiation of the program and the values at the reevaluation at which the MICs were the highest were compared by paired t test. Values are given as mean ± SD. For those patients whose MICs only decreased after the initial evaluation, we compared the data from the initial evaluation with those of the most recent reevaluation. All patients were in either the increasing MIC group or the decreasing MIC group. The VCs and PCFs of these groups also were compared with those of the MIC-equals-VC group. Longitudinal data and intergroup comparisons were made by t test. All p values < 0.05 were considered to be statistically significant.

	Results

TOP Abstract Introduction Materials and Methods Results Discussion References

 
One hundred eight patients with neuromuscular weakness underwent initial evaluations. Forty-three patients returned for reevaluation and satisfied the inclusion criteria. The 108 patients had the following diagnoses: DMD, 32 patients; amyotrophic lateral sclerosis (ALS), 30 patients; SMA, 15 patients; post-poliomyelitis syndrome, 12 patients; non-DMD myopathies, 14 patients; and miscellaneous, 5 patients. Two of the 108 patients had tracheostomy tubes. One patient did not return to clinic. Thirteen patients were unable to cooperate or were too young for the study. Thirty-one patients had VCs > 2,000 mL. Eighteen of the 108 patients were eliminated from the program because their MICs could not exceed their VCs. These 18 patients had the following diagnoses: ALS, 15 patients; SMA, 1 patient; multiple sclerosis, 1 patient; and non-Duchenne-type muscular dystrophy, 1 patient.

Of the 43 study patients, the 30 in the increasing MIC group had the following diagnoses: DMD, 9 patients (age, 22.5 ± 5.3 years); ALS, 6 patients (age, 53.9 ± 11.6 years); SMA, 3 patients (age, 11.3 ± 6.1 years); post-poliomyelitis syndrome, 6 patients (age, 61.1 ± 10.2); and miscellaneous, 6 patients (including non-Duchenne-type muscular dystrophy, 4 patients; congenital myopathy, 1 patient; and kyphoscoliosis, 1 patient; age, 33.1 ± 20.7 years). The 13 patients in the decreasing MIC group had the following diagnoses: DMD, 5 patients (age, 21.6 ± 2.3 years); ALS, 3 patients (age, 49.7 ± 16.5 years); SMA, 3 patients (age, 11.2 ± 4.0 years); and multiple sclerosis, 1 patient, and non-Duchenne-type muscular dystrophy, 1 patient, 48 and 28 years old, respectively. The relative functional abilities of the three groups of patients can be seen in Table 1 . The increasing MIC group had significantly greater muscle strength than the decreasing MIC group (p < 0.05) at the data end point but not at the initial evaluations.

View larger version (17K): [in this window] [in a new window] [Download PPT slide]   Figure 1. MICs over time for the 30 patients with increasing MICs over 3- to 6-month intervals.

	Discussion

TOP Abstract Introduction Materials and Methods Results Discussion References

It could not be confirmed how well the patients complied with the prescribed insufflation therapy. Assuming that none of them performed any regular insufflation therapy and practiced this technique only during clinic visits with us, the importance of the results of this study are not diminished. Whether the increase in air-stacked volumes was due to a training effect of practice at home or occurred only in our clinic, it is the extent of the increase in MIC that correlates with increases in assisted cough flows and, therefore, the ability to cough effectively. The higher the cough flow, the less likely are respiratory complications of neuromuscular disease.

Hypercapnia results from decreased tidal volumes due to a combination of inspiratory muscle weakness and an increase in the dynamic elastance of lung tissues.¹⁸ The latter apparently results from an inability to take the deep breaths needed to maintain pulmonary compliance. Long-term failure to take deep breaths results in chronic microatelectasis and loss of lung and chest wall elasticity with decreased static pulmonary compliance.^{19 20 21} As a consequence, the MIC becomes smaller along with the VC. We have observed patients who have been chronically underinflated for years who with only a 100-mL increase in ventilator-delivered volumes had painful stretching of intercostal musculature. In this study, we demonstrated the ability to significantly increase lung and chest wall ROM (MICs) and PCFs for the majority of patients with neuromusculoskeletal conditions despite their having severe and progressive generalized, inspiratory, and bulbar muscle weakness. In some cases, increases in MIC and assisted PCF were noted despite decreasing VC and unassisted PCF. Some of our patients with little or no measurable VC have maintained MICs of 2 L for decades with ongoing lung insufflation therapy. It is unclear whether increases in MIC reflect improvement in pulmonary compliance or are the effect of practice and better control of bulbar musculature.

Cough flows can decrease from both inspiratory and expiratory muscle weakness. Incomplete or weak glottic closure can exacerbate cough dysfunction and further decrease PCFs.²² Cough flows < 160 L/min are ineffective.²³ Assisted coughing, including air stacking, usually can increase PCFs to a point over the 160 L/min threshold.¹⁰ In 1966, Kirby and colleagues¹² demonstrated a mean increase in PCFs from 3.6 to 6.5 L/s for traumatic tetraplegic patients with cough assistance. More recently, assisted coughing has been reported to be instrumental in averting episodes of respiratory failure, hospitalization, and the need to resort to tracheostomy for patients with DMD.²⁴ Studies of nocturnal nasal ventilation for patients with neuromuscular disease that did not include air stacking and assisted coughing during intercurrent chest colds¹ failed to significantly delay a resort to tracheostomy or death.^{25 26 27 28}

The group with MICs equal to VCs had the most severely dysfunctional bulbar musculature despite having significantly greater skeletal muscle strength and VCs than the groups with MICs greater than VCs. This situation is often seen in ALS patients and is the reason that so many of these patients eventually need to undergo a tracheostomy to prolong their survival. The patients with decreasing MICs had greater bulbar muscle function than the group with MICs equal to VCs, but less than the increasing MIC group. This can be seen because their MICs exceed their VCs but fail to increase, their assisted PCFs are significantly less than those of the increasing MIC group, and they had a higher percentage of patients who developed severe dysphagia and dysarthria and required gastrostomy tubes. Their skeletal muscle strength also was not significant than and deteriorated faster than that of the increasing MIC group, so that they appeared to have a more rapid disease course. Since none of the study patients had COPD or intrinsic lung disease and since the decrease in MIC in the decreasing MIC group was not related to VC, it probably was due to bulbar muscle dysfunction and possibly, to some degree, to decreases in pulmonary compliance. On the other hand, we have found that patients with normal bulbar muscle function, such as those with spinal cord injury, can improve and maintain MICs and assisted PCFs with practice.¹⁰ In 1980, Huldtgren et al²⁹ first demonstrated that maximal insufflation therapy could increase MIC after spinal cord injury.

In conclusion, the MICs of the majority of patients (30 of 43 [70%]) with neuromuscular disease can increase, resulting in significantly increased assisted PCF. The most important exception is that of bulbar ALS patients.

	Footnotes

 
Abbreviations: ALS = amyotrophic lateral sclerosis; DMD = Duchenne muscular dystrophy; MIC = maximum insufflation capacity; PCF = peak cough flows; ROM = range of motion; SMA = spinal muscular atrophy; VC = vital capacity

This research was performed at University Hospital, UMDNJ-New Jersey Medical School, Newark, NJ.

	References

TOP Abstract Introduction Materials and Methods Results Discussion References

 

1. Bach, JR, Rajaraman, R, Ballanger, F, et al (1998) Neuromuscular ventilatory insufficiency: the effect of home mechanical ventilator use vs. oxygen therapy on pneumonia and hospitalization rates. Am J Phys Med Rehabil 77,8-19[CrossRef][ISI][Medline]
2. Hoffman, LA (1987) Ineffective airway clearance related to neuromuscular dysfunction. Nurs Clin North Am 22,151-166[Medline]
3. Ferris, BG, Pollard, DS (1960) Effect of deep breathing and quiet breathing on pulmonary compliance in man. J Clin Invest 39,143-149
4. Hall, W (1977) Respiratory failure as a complication of neuromuscular disease. Adv Neurol 17,317-324[Medline]
5. McCool, FD, Mayewski, RF, Shayne, DS, et al (1986) Intermittent positive pressure breathing in patients with respiratory muscle weakness: alterations in total respiratory system compliance. Chest 90,546-552[Abstract/Free Full Text]
6. Estenne, M, Heilporn, A, Delhez, L, et al (1983) Chest wall stiffness in patients with chronic respiratory muscle weakness. Am Rev Respir Dis 128,1002-1007[ISI][Medline]
7. Ferris, BG, Mead, J, Whittenberger, JL, et al (1952) Pulmonary function in convalescent poliomyelitis patients: compliance of the lungs and thorax. N Engl J Med 247,390-393
8. Estenne, M, Gevenois, PA, Kinnear, W, et al (1993) Lung volume restriction in patients with chronic respiratory muscle weakness: the role of microatelectasis. Thorax 48,698-701[Abstract]
9. Leith, DE (1977) Cough. Brain, JD Proctor, D Reid, L eds. Lung biology in health and disease: respiratory defense mechanisms, part 2 ,545-592 Marcel Dekker New York, NY.
10. Bach, JR (1993) Mechanical insufflation-exsufflation: comparison of peak expiratory flows with manually assisted and unassisted coughing techniques. Chest 104,1553-1562[Abstract/Free Full Text]
11. Bach, JR (1995) Amyotrophic lateral sclerosis: predictors for prolongation of life by noninvasive respiratory aids. Arch Phys Med Rehabil 76,828-832[CrossRef][ISI][Medline]
12. Kirby, NA, Barnerias, MJ, Siebens, AA (1966) An evaluation of assisted cough in quadriparetic patients. Arch Phys Med Rehabil 46,705-710
13. Shapiro, BA, Harrison, RA, Kacmarek, RM, et al (1985) Clinical application of respiratory care. ,84-87 Year Book Medical Publishers Chicago, IL.
14. Bach, JR (1993) Pulmonary rehabilitation in neuromuscular disorders. Semin Respir Med 14,515-529
15. Emery, AEH (1997) Diagnostic criteria for neuromuscular disorders 2nd ed. Royal Society of Medicine Press London, UK.
16. Willig, TN, Bach, JR, Rouffet, MJ, et al (1995) Correlation of flexion-contractures with upper extremity function for spinal muscular atrophy and congenital myopathy patients. Am J Phys Med Rehabil 74,33-38[ISI][Medline]
17. Bach, JR, McKeon, J (1991) Orthopedic surgery and rehabilitation for the prolongation of brace-free ambulation of patients with Duchenne muscular dystrophy. Am J Phys Med Rehabil 70,323-331[ISI][Medline]
18. Misuri, G, Lanini, B, Gigliotti, F, et al (2000) Mechanism of CO₂ retention in patients with neuromuscular disease. Chest 117,447-453[Abstract/Free Full Text]
19. Gibson, GJ, Pride, NB, Newsom Davis, J, et al (1977) Pulmonary mechanics in patients with respiratory muscle weakness. Am Rev Respir Dis 115,389-395[ISI][Medline]
20. De Troyer, A, Deisser, P (1981) The effects of intermittent positive pressure breathing on patients with respiratory muscle weakness. Am Rev Respir Dis 124,132-137[ISI][Medline]
21. De Troyer, A, Borenstein, S, Cordier, R (1980) Analysis of lung volume restriction in patients with respiratory muscle weakness. Thorax 35,603-610[Abstract]
22. Scanlan, CL (1995) Chest physical therapy. Scanlan, CL Spearman, CB Sheldon, RL eds. Egan’s fundamentals of respiratory care 6th ed. ,785-794 Mosby Year Book St. Louis, MO.
23. Bach, JR, Saporito, LR (1996) Criteria for extubation and tracheostomy tube removal for patients with ventilatory failure: a different approach to weaning. Chest 110,1566-1571[Abstract/Free Full Text]
24. Bach, JR, Ishikawa, Y, Kim, H (1997) Prevention of pulmonary morbidity for patients with Duchenne muscular dystrophy. Chest 112,1024-1028[Abstract/Free Full Text]
25. Piper, AJ, Parker, S, Torzillo, PJ, et al (1992) Nocturnal nasal IPPV stabilizes patients with cystic fibrosis and hypercapnic respiratory failure. Chest 102,846-850[Abstract/Free Full Text]
26. Piper, AM, Sullivan, CE (1994) Effects of short-term NIPPV in the treatment of patients with severe obstructive sleep apnea and hypercapnia. Chest 105,434-440[Abstract/Free Full Text]
27. Raphael, J-C, Chevret, S, Chastang, C, et al (1994) Randomised trial of preventive nasal ventilation in Duchenne muscular dystrophy. Lancet 343,1600-1604[CrossRef][ISI][Medline]
28. Leger, P, Bedicam, JM, Cornette, A, et al (1994) Nasal intermittent positive pressure ventilation: long-term follow-up in patients with severe chronic respiratory insufficiency. Chest 105,100-105[Abstract/Free Full Text]
29. Huldtgren, AC, Fugl-Meyer, AR, Jonasson, E, et al (1980) Ventilatory dysfunction and respiratory rehabilitation in post-traumatic quadriplegia. Eur J Respir Dis 61,347-356[ISI][Medline]

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